1. Field of the Invention
The present invention relates generally to the sterilization and disinfection of agricultural and botanical products such as botanical powders. More particularly, the present invention is directed towards the use of heterogeneous biphase sterilization (HBS) technology whereby contaminated agricultural products are contacted with an oxidant such as nascent atomic oxygen and/or hydroxyl radicals thus resulting in the oxidization and destruction of the contaminating microorganisms.
2. Description of the State of Art
Herbal powders comprise a large portion of the botanical products sold in the dietary supplement market. These powders are processed by milling raw whole herbs or plants. The resultant powders have a natural profile of chemical constituents unaltered from the plants themselves. However, they also are generally contaminated with the same microbial organisms found on the botanical raw materials which are harvested from farms or are collected from wild fields. Therefore, it is essential to remove the microbial contamination from the herbal powders before they are incorporated into a finished dose form and sold into the market.
Currently, ethylene oxide and gamma irradiation are the dominant modes for sterilizing botanical powders. However, these technologies have been challenged recently due to concerns that gamma irradiation and ethylene oxide residuals found in botanical powders may potentially be harmful to human health. Already Europe and Japan have implemented regulations against the use of one or the other of these technologies.
Other sterilization techniques for botanicals include the application of heat and/or steam. Unfortunately, intense heat and/or steam likely damage the active ingredients in the plants and have proven unreliable in permanently eliminating microbial spores that regenerate after cooling.
Another sterilization technology, ozonization, has recently been mentioned for use with botanical products, but it is uncertain if this technology will be able to permanently eliminate microbes. From a cost point of view, ozonilysis requires significant investment for building a specific facility with property and equipment because ozone has to be generated on site. These facilities are also extremely dangerous due to the highly explosive nature of ozone production.
U.S. Pat. No. 5,460,845, issued Oct. 24, 1995 to Delmassa, et al., shows treating the surface of seeds, nuts, grains, fruits and spices in a dehumidifying chamber, exposing the food to H2O2 and H2O vapor under vacuum, followed by removing the peroxide to 38 mm Hg, followed by increasing the pressure to 400-580 mm Hg, for a 3-30 minute exposure. U.S. Pat. No. 5,514,403, issued May 7, 1996 to Webb, et al., teaches killing bacteria on animal carcasses by spraying with superheated steam at 250-300xc2x0 F. for 1-5 seconds followed immediately by spraying with a cooling liquid for 5-10 seconds. U.S. Pat. No. 5,523,053, issued Jun. 4, 1996 to Daniel H. Dudek, describes sterilizing spices or herbs by dropping the material into pressurized steam sterilization chambers successively for a predetermined period of time, followed by gradual depressurization to atmospheric pressure.
U.S. Pat. No. 5,593,714, issued Jan. 14, 1997 to Gerald P. Hirsch, describes placing a food product in a compressible package at 25,000 psi and 18-23xc2x0 C. for at least 5 days and optionally adding an anti-oxidant. U.S. Pat. No. 5,641,530, issued Jun. 24, 1997 to T. C. Chen, teaches treating foodstuffs with 0.005% to 0.035% H2O2 and 0.005 to 0.1% H3PO4 or C6H5COOH. U.S. Pat. No. 5,711,981, issued Jan. 27, 1998 to Wilson, et al., describes treating meats by removing surface water by air blowing, steam heating at pressure greater than atmospheric, and chilling by spraying with water.
All of these techniques have suffered from one or more of the following problems: (1) denaturation of protein in food stuff, (2) insufficient bacterial kill, (3) deleterious color change, (4) unacceptable flavor modification, (5) inadequate control of the process in large scale operations, (6) expensive and elaborate process equipment is needed, (7) high atmospheric pressures are required, and (8) difficult to process powdered material with large surface area.
As an example, most of the techniques discussed above require applying a vacuum prior to flushing. This requires the vacuum pump to remove air from an air tight treatment chamber at a prodigious rate, engendering frequent mechanical breakdowns, or slowing the treatment process, which makes the apparatus less economical and less desirable from an industrial perspective. It is an object of the present invention to overcome the difficulties and disadvantages of the prior art.
Because of the multifarious reasons set forth above, existing methods for sterilizing botanical powders are unsatisfactory. The challenge is to develop a competitively priced sterilization process capable of permanently eliminating microbial contamination in botanical powders while maintaining their original chemical and physical properties. These properties include bulk density, flowability, compressibility, mass distribution, moisture content, color, odor and most importantly, chemical composition.
Accordingly, one object of this invention is to provide a method and apparatus for the sterilization and disinfection of agricultural products.
Another object of this invention is to provide a method of effectively killing microorganisms that exist within botanical powders.
Additional objects, advantages, and novel features of this invention shall be set forth in part in the description and examples that follow, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by the practice of the invention. The objects and the advantages of the invention may be realized and attained by means of the instrumentalities and in combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with the purposes of the present invention, as embodied and described therein, the process of this invention may comprise contacting at ambient pressure microbial contaminated surfaces with nascent oxygen and/or hydroxyl radicals.